A comprehensive survey of the analytical, numerical and experimental methodologies for dynamics of multibody mechanical systems with clearance or imperfect joints

http://repositorium.sdum.uminho.pt/bitstream/1822/8885/1/ARI-04-2006.pdf

A study on dynamics of mechanical systems including joints with clearance and lubrication

https://repositorium.sdum.uminho.pt/bitstream/1822/23277/1/6.7.12%202009.pdf

Modeling and simulation of wear in revolute clearance joints in multibody systems

A general regularized contact model, including normal compliance, energydissipation, and tangential friction, is described in this paper. Thenormal damping coefficient is formulated as a function of the coefficientof restitution e and the impact velocity only; the results areenergy-consistent, with continuous force progression at the beginningand end of the impact, for both small and large values of e.The introduced seven parameter friction model based on an explicitformulation of the friction forces is suitable for real-timeapplications. The friction forces are split into its sliding andsticking contribution and a temporal lag effect, the dwell-time, isincluded using a novel dwell-time dependent stick state variable. Several examples are presented to demonstrate the features of thisgeneral contact model. The simulation results for a double pendulumhitting a plane are obtained, and a comparison with a benchmark problem shows the model behavior is in good agreement with published results.

A Regularized Contact Model with Asymmetric Damping and Dwell-Time Dependent Friction

https://repositorium.sdum.uminho.pt/bitstream/1822/23521/1/6.7.15%202009.pdf

Dynamics of spatial flexible multibody systems with clearance and lubricated spherical joints

Analysis of impact problems in the presence of any tangential component of impact velocity requires a friction model capable of correct detection of the impact modes. This paper presents a formulation for the analysis of impact problems with friction in open-loop multibody mechanical systems. The formulation recognizes the correct mode of impact; i.e., sliding, sticking, and reverse sliding. Poisson’s hypothesis is used for the definition of the coefficient of restitution, and thus the energy gains inherent with the use of the Newton’s hypothesis are avoided. The formulation is developed by using a canonical form of the system equations of motion using joint coordinates and joint momenta. The canonical momentum-balance equations are solved for the change in joint momenta using Routh’s graphical method. The velocity jumps are calculated balancing the accumulated momenta of the system during the impact process. The impact cases are classified based on the pre-impact positions and velocities, and inertia properties of the impacting systems, and expressions for the normal and tangential impulse are derived for each impact case. The classical problem of impact of a falling rod with the ground (a single object impact) is solved with the developed formulation and verified. Another classical problem of a double pendulum striking the ground (a multibody system impact) is also presented. The results obtained for the double pendulum problem confirms that the energy gain in impact analysis can be avoided by considering the correct mode of impact and using the Poisson’s instead of the Newton’s hypothesis.

M. F. O. S. Pereira

Papers

Frictional Impact Analysis in Open-Loop Multibody Mechanical Systems